Electron discharge device



March 7, 1950 RlsHELL 2,499,974

ELECTRON DISCHARGE DEVICE Filed March 20, 1948 JNVENTOR. jzajye Lilia/Z412 W MMA filial/76y Patented Mar. 7, 1950 ELECTRON mscnsace DEVICE George L. Rishell, Emporium, Pa., assignor to Sylvania Electric Products, Inc., a corporation of Massachusetts Application March 20, 1948, Serial No. 16,056

This invention relates to electron discharge devices such as are used in radio receivers.

The electron discharge device comprises an envelope within which are mounted a plurality of electrodes variously connected to leads which are sealed through a wall of the envelope. The electrodes interior the envelope are arranged to form an electrode assembly. It is not unusual to find electron discharge devices which contain more than one electrode assembly Within a single envelope. For an illustration of tubes of this general type, reference may be'had to my Patent Number 2 284,495, issued May 26, 1912, which discloses a duodiode triode, the triode and diode electrode assemblies there shown being coaxially arranged one above the other.

In the manufacture of electron devices of this general class, each electrode assembly is arranged between two transverse insulating wafers which position the individual electrode assemblies. Referring, particularly, to the duodiode section, a prior art practice has been to form the diode plates of arched strips of metal having tabs at the axial extremities of the anode structure penetrating suitable wafers that serve to fix the electrodes in proper mutual position. The anode of this prior art duodiode uses an undue mass of metal which impairs the resulting operating characteristics. Furthermore, the metallic structures of electron discharge tubes are outgassed during manufacture so that the outgassing operation is normally made more difficult as the mass of the metallic portions of the discharge device is increased.

It is an object of this invention to provide an electron tube having an anode structure of simplified construction which uses no more than one insulating wafer for support. It is among the further objects of the invention to provide a novel and improved multiple diode electrode assembly having uniform and improved characteristics. A further object of the invention is to provide an anode construction of minimum size. Small metallic electrodes are of particular advantage in the high frequency electrical spectrum.

In the following specific disclosure a duodiode electrode assembly is shown incorporating an illustrative form of the novel anode.

For a more complete understanding of the invention and of further features of novelty, attention is directed to the following description taken in connection with the accompanying drawing wherein:

Figure l is an elevation partially in section of an electron tube embodying the invention.

9 Claims. (Cl. 25027.5)

' 2 Figure 2 is a plan view on line 2-2 of Figure 1, Figure 3 is a view in perspective of a new anode. Referring to Figure 1, an envelope I I has multiple leads AI-I sealed through the header or Wall 12 of the envelope. Within the envelope, a pentode electrode assembly l4 is'shown together with a duodiode electrode assembly I5.

Duodiode electrode assembly [5 comprises a cathode It heated by a filament ll; Cathode l6 fits through an aperture in a transverse insulating wafer l8 having other apertures I9, 20, 2|; 22, 23, 24 for receiving electrode tabs.

The anode portions of the duodiode electrode assembly are each formed of a unitary piece of metal 25 (Figure 3) having a first wing portion 21 and a second wing portion 25 substantially at right angles to each other. The free end of portion 2'! is formed at 21a to partly enclose the oathode in the assembly, as will appear. Portion 26 has integral tabs 28 and 29, and portion 21, likewise, has an integral tab 30, although the number of tabs in each portion is obviously susceptible'to design variations. i

In assembling the electrodes (Fig. 2) one anode 25 is mounted on insulating wafer 48 with tabs 28, 29 and 30 passing through apertures 20, [9, 2| respectively. Tabs 29 and 30 are bent over, retaining anode 25 in position. A connecting strap 31 is welded to tab 28 and a sealed-through lead F. A second anode 25 is similarly mounted with the tabs fitted through apertures 22, 23, 24 and with a connecting strap 38 welded to tab 28 and a sealed-through lead E. The anodes are illustrated as assembled in pinwheel fashion, each with part 21 being substantially tangential to the curve of end portion 21a and part 26 developing away from cathode l6 at an angle to the direction of departure of part 21. It is obvious that the number of tabs used, the tabs bent over and the tab used as a connecting tie-point are a matter of design.

For illustrative purposes, electrode assembly 54 comprises a section of cathode It, a first grid 32, a second grid 33, a third grid 34, an anode 35 and a shield cage 36. Electrode assembly l4 may include any number and arrangement of electrodes. The anodes are shielded from electrode assembly M by metallic box shield 3i covering the anodes and secured to wafer I8.

From the above description it may be seen that one insulating wafer is used for the duodiode electrode assembly and that the interelectrode capacity between anode sections is relatively small, the wing portions of the anode extending away from one another. This is desirable for 3 high frequencies where the interelectrode capacity affects the efliciency and operations of the electron tube. The angularly arranged wing portion having at least one tab of each wing bent over, as illustrated, results in a rigid anode assembly.

What isclaimed is:

l. Anv electronic tube including. a slender cathode and a plurality of L-shaped anodes supported in active relation to said cathode, each ofsaid anodes having a formed end portion, said end portions partially surrounding'together'sub stantially encirclin the same part said cathode. 2. An electronic tube including. a. slender.

cathode and a plurality of like L-shaped anodes symmetrically disposed in pin-wheel fashion about said cathode, each of saidanodes having a curved end portion said end portions together surrounding the same portion of the length of said cathode.

3. An electronic. tubehaving a. slender cathode, an apertured insulating. wafer penetrated'by said cathode, and a plurality of anodes mounted nor.- mally to the plane of said wafer andin supported relation to said cathode, each of said anodes having a formed end portion partially surrounding saidrcathode and includinga lateral tab penetrating. said wafer.

44 An electronic tube having a slender cathode, an apertured insulating wafer penetrated by said cathode, and a plurality of anodes supported in active. relation to said cathode, each of said anodes having a substantially, radial wing portion, terminating. adjacent said cathode and a substantially tangential wing portion secured to said radialwing portion, each of said wing por-' tions. includingv alateral tab. penetrating said wafer.v

5I.An electrode comprising a pair of 'angularly related wing portions, at least one of said wing portions terminating, in an arcuate portion, said one wing portion extending tangentially away from said arcuate portion and a number of lateral tab's extending'from the same side'of said wing portions.

6.' An electronic tube having a slender cathode, an.insulating wafer penetrated by said cathode andlan anode supported perpendicularly to'said wafer and in active relation to said cathode, said anode having, a wing portion terminating in formed lend adjacentsaid cathode, said wingpor tion extending tangentially away from said formed end and a second wing portion angularly secured to said radial wing portion each of said wing portions including a lateral tab penetrating said wafer.

7. An electronic tube having a slender cathode, an apertured insulatingwafer penetrated by said cathode, and a plurality ofanodes supported in active relation to said cathode, each of said anodes having a wing portion terminating adjacent said cathode and extending away from said cathode-along one direction and another wing portionextending another direction, each of said. wing portions including a parallel tab penetrating said wafer.

8. An electronic tube having a slender cathode, an apertured insulating Wafer penetrated by said cathode, and a plurality of anodes having active portions formed as substantially complementary sections about the same length of said cathode, and supporting portions extending tangentially away from said formed portions, said anodes each beingsecured along one edge to said insulating wafer;

9. An electronic tube having a slender cathode, an'apertured insulating wafer penetrated by said cathode, and a plurality of anodes having active portions formed as substantially complementary sectionsabout the same length of said cathode, and supporting'portions extending tangentially away from said formed portions, said anodes each being secured along one edge to said insulating wafer,iportions of said anodes being bent at an angle tothe' remainder for maintaining them on edge on said wafer.

GEORGE L. RISHELL.

REFERENCES CITED The following references are of record in the fileof this patent:

UNITED STATES PATENTS Number Name Date 2,113,005 Smith Apr. 5, 1938 2,460,398 Schade Feb. 1, 1949 FOREIGN PATENTS Number Country Date 430,436 Great Britain June 19, 1935 510,703 Great Britain Aug. 4, 1939 5,426 Australia Dec. 17, 1931 

